Escapement mechanism for typewriters



Filed March 5, 1965 April 4, 1967 F. H. CANNY 3,312,322

' ESCAPEMENT MECHANISM FOR TYPEWRITERS 5 Sheets-Sheet 1 f' k INVENTOR.

FLOYD H. CANNY Mafil AGENT F. H. CANNY ESCAPEMENT MECHANISM FOR TYPEWRITERS April 4, 1967 5 Sheets-Sheet 2 Filed March 5, 1965 INVENTOR;

FLOYD H. CANNY AGENT A ril 4, 1967 F. H. CANNY 3,31 2

ESCAPEMENT MECHANISM FOR TYPEWRITERS Filed March 5, 1965 5 Sheets-Sheet 5 INVENTOR.

AGENT 3,312,322 ESCAPEMENT MECHANISM FOR TYPEWRITERS Floyd H. Canny, Syracuse, N.Y., assignor to SCM Corporation, New York, N.Y., a corporation of New York Filed Mar. 5, 1965, Ser. No. 437,504 2 Claims. (Cl. 197-82) This invention relates to typewriting machines or the like and more particularly to the mean-s by which the carriage of a manual typewriter is automatically spaced in the letter feed direction.

As revealed in the prior art for the automatic spacing of a manual typewriter carriage, a US. Patent 744,424 issued to Steiger on Nov. 17, 1903, discloses a typewriter rack type escapement with a pair of dogs that alternately engage the carriage rack to space the carriage in a letter feed direction during normal spacing and with one of these dogs cooperating with a third dog to alternately engage the carriage rack during automatic repeat spacing. An adjustable Weight is employed to vary the rate of carriage travel during repeat spacing.

US. Patent 937,336 issued to Stickney on Oct. 19, 1909, also discloses a rack type escapement with a pair of dogs that alternately engage the carriage rack to ad- Vance the carriage in the letter feed direction during normal typing, and in this case the same dogs are used. to advance the carriage during repeat spacing. The Stickney mechanism provides for varying the rate of carriage travel during repeat spacing by removing a part and replacing the part with one of a different weight.

These rack type escapement mechanisms have a disadvantage in that they have an inherent undesirable characteristic of a clicking noise caused by the dogs riding over the teeth of the rack each time the carriage is returned to the left margin.

A-U.-S. Patent 3,028,942 issued to Page on Apr. 10, 1962, discloses an automatic repeat spacing mechanism forfla manual typewriter having a toothed starwheel type escapement. When repeat spacing is desired, an actuating pawl is moved within the path of the starwheel teeth and the actuating pawl causes repeated normal cycling of the toothed star wheel escapement. This patent has a disadvantage in that it discloses no provision for varying the rate of carriage travel during repeat spacing.

Most all manual typewriters do not provide for automatic repeat spacing of the carriage and quite often a typist desires to advance the carriage several letter spaces in the letter feed direction. This is usually accomplished by tabulation or by repeatedly depressing the space bar. In either case, if done frequently, the typist finds it inconvenient and time consuming.

It is therefore the main object of this invention to provide a convenient and efiicient automatic repeat spacing mechanism for manual typewriters. Another object of this invention is to provide an automatic repeat spacing mechanism for a manual typewriter having a toothed starwheel type escapement with a provision for eliminating the undesirable clicking noise when the carriage is returned to the left margin.

Still another object of this invention is to provide an automatic repeat spacing mechanism for a manual typewriter by adding a second independent escapement means for repeat spacing that is easily adaptable to a typewriter having a toothed starwheel escapement.

A further object of this invention is to provide an automatic repeat spacing mechanism for a manual typewriter having a means for adjusting the rate of carriage travel during repeat spacing.

Other Objects and further novel features of the present invention will become more fully apparent from the appended claims and as the ensuing detailed description nite States Patent and discussion proceeds in conjunction with the accompanying drawings, in which:

FIGURE 1 is a left side elevational view showing a conventional and a repeat escapement mean-s in a normal inoperative position of the present invention;

FIGURE 2 is a rear perspective view of the two escapement means;

FIGURE 3 is a left side elevational view of the two escapement means with the conventional escapement in operative position;

FIGURE 4 is a left side elevational view of the two escapement means with the repeat escapement means in operative position; and

FIGURE 5 is a rear elevational view of the escapement starwheel and a repeat actuator shown in two positions.

Referring now to the drawings, FIGURE 1 illustrates a typewriter having a side frame 10, a carriage 12, and a repeat spacing mechanism 14, constructed in accordance with the principles of the present invention for moving carriage 12 by repetitive stepping action in the letter feed direction. The carriage 12 is biased in the letter feed direction by means of a usual main spring and tape assembly 15. This novel mechanism includes a normally disengaged repeat actuator 16 and a pendulum 18 wherein a pendulum weight 20 is adjustably mounted varying the rate of carriage travel during repeat spacing. Repeat actuator 16 is engaged with escapement starwheel 22 to effect repeat spacing of the carriage 12 by an arm 104 of the conventional escapement 26 when .a space bar 28 is depressed beyond a normal single spacing depth and rocks the conventional escapement 26 out of engagement from starwheel 22.

As best shown in FIGURE 4, the conventional escapement 26 includes the starwheel 22 which has a plurality of circumferentially spaced teeth 30. The starwheel 22 is rigidly mounted to a shaft 32 that is pivotally mounted in the machine frame and has a pinion '34 rigidly mounted thereon that meshes with the carriage rack 36 (FIGURE 1). A pair of dogs 38 and 40 are supported by a rocker body 42 which-is pivotally mounted to frame member 44 by two bearing studs 46 (only one side shown). The dog 38 (the stepping dog) is slidably mounted to the rocker body 42 by a control pin 48 extending through an elongated aperture (not shown) in dog 38 and is biased in the letter feed direction against a tooth of starwheel 22 by a spring 50 which has one end. connected to a spring anchor 52 formed from dog 38 and has the other end connected to .a guide pin 54. The dog 40 (the holding dog) is integral with the rocker body 42. Both dogs 38 and 40 are arranged in such a manner to alternately engage the starwheel teeth to provide the controlling incremental stepping movements of the carriage in the letter feed direction by a normal depression of the space bar 28.

Referring to FIGURE 1, a normal depression of space bar 28 is when a lever 56 contacts a torsion spring 58 that is securely mounted to the side frame 10. The lever 56 and a link 60 are rigidly mounted at their common end to a shaft 62 which is pivotably mounted in the side frame. Link 60 is pivotably mounted near its rearward end to a shorter link 64 that is pivotably mounted to a frame member by a screw 66. The depression of the space bar 28 drives link 60 to the left to contact an adjustable screw 68 having a lock nut 69 threaded in rocker 42 and pivots rocker 42 clockwise about studs 46 (FIG- URE 3) for a normal single space actuation. When the space bar 28 is released, a spring 70, having one end connected to link 64 and the other end connected to link 60, biases link 60 toward the right to return space bar 28 to its normal rest position.

Referring now to FIGURE 2, a bracket 72 is rigidly assembled to frame member 74 by screws 76 and has an upward formed support 78 on which a shaft 80 is rigidly assembled. The shaft 80 has a sleeve 82 slidably and pivotably mounted thereon with the repeat actuator 16 rigidly mounted on the forward end of the sleeve and with the pendulum 18 rigidly mounted on the rearward end of the sleeve. A tension spring 84, having one end connected to a rigid frame member (not shown) and the other end connected to a spring anchor 86 formed from a pendulum arm 83, biases the repeat escapement assembly 14 away from starwheel 22 to a limited position determined by arm 88 abutting against extension 99 of bracket 72. The extension 99 has a pointed finger 92 that extends into a slot 94 in arm 88 for aligning repeat actuator 16 with the starwheel 22 for proper engagement therewith.

The pendulum weight 26 is adjustably mounted to the lower end of arm 88 by a screw 96 that extends through an elongated slot 98 in arm 88 and is threaded into the weight 20. A lock washer 1% under the head of screw 96 insures a rigid assembly. A guide stud 102 is rigidly assembled to weight 20 and also extends through elongated slot 98 of arm 88. v The combination of the screw 96 and the stud 102 permits varyingthe distance of weight 2%) from its fulcrum shaft 80 while maintaining the balance of the weight with respect to arm 88 which varies the rate of carriage travel during repeat spacing.

An arm 104 is rigidly assembled substantially midway on rocker body 42 by two formed fingers 106 and a screw 108. Arm 104 has an upward formed extension 110 that terminates at end 112 which is in line with but away from the outer surface of arm 88. The clearance between end 112 and arm 38 is sufficient to allow rocker body 42 to rock for normal stepping operations without interference.

To effect automatic repeat spacing, the space bar 28 (FIGURE 1) is first depressed to the normal depth against torsion spring 58 and then is further depressed causing spring 58 to yield. Link 60 is now driven further to the left which pivots the conventional escapement 26 clockwise a sufficient amount to carry dogs 38 and 4% out of the path of starwheel 22 and a sufiicient amount to cause end 112 of arm 104 to contact arm 88 and drive the repeat escapement'14 along shaft 80 until actuator 16 straddles the starwheel 22, shown best by FIGURE 4. A predetermined timing of this motion is such that actuator 16 straddles the starwheel 22 just before the dog 40 leaves the teeth of the starwheel. The clockwise movement of the conventional escapement 26 when driving the repeat escapement 14 into operative position is limited by an adjustable screw 113 with a lock nut 11S abutting against a rigid stop 117, shown best in FIGURE 4.

During the normal depression of the space bar 28 when the starwheel 22 steps from the stepping dog 38 to the holding dog 40, the starwheel 22 rotates approximately one-half a tooth pitch and is then in position (FIGURE for repeat actuator 16 to straddle the starwheel Without repeat actuator dogs 114 and 116 interfering with the starwheel teeth 30.

' The repeat actuator 16 (FIGURE 5) is constructed with two integral arms 118 and 120 that provide the respective actuator dogs 114 and 116 at their ends. Dog 114 'has a cam surface 122 and dog 116 has a cam surface 124 which are so orientated with respect to each other that only one cam surface can be contacted by a starwheel tooth 30' at a time. The position of the repeat actuator 16 and the starwheel 22 (illustrated by the solid lines) showing the right dog 116 in the path of the starwheel teeth is the position at which the repeat action begins. As starwheel 22 starts to rotate clockwise from the influence of the carriage rn-ainspring 15, a starwheel tooth 30 contacts cam surface 124 of the right actuator dog 116 and pivots the repeat actuator 16 counterclockwise about shaft 80. This action has now positioned the repeat actuator left dog 114 in the path of its approaching cooperating starwheel tooth (illustrated by broken lines). As this approaching starwheel tooth contacts cam surface 122 of the left dog 114, the notating force of the starwheel causes a tooth to cam along cam sur face 122 and pivot actuator 16 clockwise which again positions the right dog 116 in the path of its next approaching cooperating starwheel tooth. This alternate cam action continues and al lows continuous controlled movement of the carriage in the letter feed direction as long as the space bar 28 is held depressed in the repeat position.

When the carriage 12 has reached a desired position, the space bar 28 (FIGURE 1) is released and torsion spring 58 and tension spring 70 return space bar 28 and link to their normal rest positions. A spring 130, having one connected to an adjustable spring anchor 132 with a lock nut 134 and having the other end connected to a rigid member 136, is now free to bias rocker body 42 counter-clockwise to its normal position determined by the rocker body abutting against an adjustable stop 138. The return of rocker body 42 to its normal position allows spring 84 to bias repeat escapement mechanism 14 out of the path of starwheel 22 to its normal inoperative position allowing dog 38 of the conventional escapement to reengage the starwheel teeth 30.

During the repeat spacing operation, when the starwheel teeth contact the cam surface of each repeat actuator dog, the energy possessed by the repeat actuator to retard the rotation of the starwheel is dependent mainly upon the distance at which the pendulum weight 2 0 is located from the axis of shaft 80. The pendulum weight may be adjusted within the limits of the elongated slot 98. If the distance is increased, the pivotable resistance of the repeat actuator is increased and the carriage moves slower, whereas if the distance is decreased, the pivotable resistance of the repeat actuator is decreased and the carriage moves faster.

The invention may be embodied in other specific forms without departing from the spinit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing descrip tion, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A typewriter comprising:

(a) a frame;

(b) a carriage movably mounted on said frame;

(0) means for biasing said carriage in a letter feed direction;

(d) a toothed member operatively connected to said carriage;

(e) a first escapement mechanism including:

(1) a rockable member;

(2) a pair of dogs mounted on said rockable member, said pair of dogs rockable from an operative position to an inoperative position and in said operative position engageable with said toothed member for controlling a normal single step movement of said carriage in the letter feed direction under the influence of said biasing means;

(3%) an arm rigidly mounted on said rockable mem (f) a second escapement mechanism including a pair of dogs mounted for slidable movement from an inoperative position to an operative position and in said operative position engageable with said toothed member for controlling continuous stepping movements of said carriage in the letter feed direction under the influence of said biasing means; and

(g) key operable means for rocking said first escapement mechanism from said operative position to said inoperative position causing said arm to contact and simultaneously move said second escapement mechanism from said inoperative position to said operative position.

2. A typewriter or the like comprising:

(a) a frame;

(b) a carriage movably mounted on said frame;

(0) means for biasing said carriage in a letter feed direction;

(d) a first escapement mechanism operatively connected to said carriage for normally controlling incremental stepping movements of said car-riage in the letter feed direction;

(e) a second escapement mechanism operatively connected to said carriage independent of said first escapement mechanism for controlling automatic repetitive incremental stepping movements of said carriage in the letter feed direction comprising:

(1) a pair of dogs alternatively connected to said carriage for said automatic repetitive incremental stepping movements;

(2) an arm rigidly connected at an upper end to said pair of dogs; and

(3) a weight adjustably connected at a lower end of said arm to actuate said pair of dogs at a rate determined by an oscillative movement of said Weight;

(f) a member carried by said first escapement mechanism and operable to move said second escapement mechanism upon movement of said first escapement; and

(g) keyboard operable means operable to rock said first escapement mechanism out of control of said carriage causing said member to contact and move said second escapement mechanism into control of said carriage.

References Cited by the Examiner UNITED STATES PATENTS 458,567 9/1891 Frankly 197-82 X 536,303 3/1895 Stackhouse 197-87 X 626,936 6/1899 Shimer 197-85 700,608 5/1902 Beals 197-84 744,424 11/1903 Steiger 197-64 779,407 1/ 1905 Brown 197-82 937,336 10/ 1909 Stickney 197-82 944,794 12/ 1909 Latta 197-85 1,414,167 4/1922 Barr 197-82 1,921,490 8/ 1933 Stickney 197-82 3,028,942 4/1962 Page 197-88 3,212,616 10/1965 Frechette et a1 197-82 FOREIGN PATENTS 843,336 3/1939 France.

ROBERT E. PULFREY, Primary Examiner.

E. T. WRIGHT, Assistant Examiner. 

1. A TYPEWRITER COMPRISING: (A) A FRAME; (B) A CARRIAGE MOVABLY MOUNTED ON SAID FRAME; (C) MEANS FOR BIASING SAID CARRIAGE IN A LETTER FEED DIRECTION; (D) A TOOTHED MEMBER OPERATIVELY CONNECTED TO SAID CARRIAGE; (E) A FIRST ESCAPEMENT MECHANISM INCLUDING: (1) A ROCKABLE MEMBER; (2) A PAIR OF DOGS MOUNTED ON SAID ROCKABLE MEMBER, SAID PAIR OF DOGS ROCKABLE FROM AN OPERATIVE POSITION TO AN INOPERATIVE POSITION AND IN SAID OPERATIVE POSITION ENGAGEABLE WITH SAID TOOTHED MEMBER FOR CONTROLLING A NORMAL SINGLE STEP MOVEMENT OF SAID CARRIAGE IN THE LETTER FEED DIRECTION UNDER THE INFLUENCE OF SAID BIASING MEANS; (3) AN ARM RIGIDLY MOUNTED ON SAID ROCKABLE MEMBER; (F) A SECOND ESCAPEMENT MECHANISM INCLUDING A PAIR OF DOGS MOUNTED FOR SLIDABLE MOVEMENT FROM AN INOPERATIVE POSITION TO AN OPERATIVE POSITION AND IN SAID OPERATIVE POSITION ENGAGEABLE WITH SAID TOOTHED MEMBER FOR CONTROLLING CONTINUOUS STEPPING MOVEMENTS OF SAID CARRIAGE IN THE LETTER FEED DIRECTION UNDER THE INFLUENCE OF SAID BIASING MEANS; AND (G) KEY OPERABLE MEANS FOR ROCKING SAID FIRST ESCAPEMENT MECHANISM FROM SAID OPERATIVE POSITION TO SAID INOPERATIVE POSITION CAUSING SAID ARM TO CONTACT AND SIMULTANEOUSLY MOVE SAID SECOND ESCAPEMENT MECHANISM FROM SAID INOPERATIVE POSITION TO SAID OPERATIVE POSITION. 